@lategoodbye
I use this kernel:
https://archlinuxarm.org/packages/aarch64/linux-aarch64I haven't looked at the network problem in detail,
but various network services are having problems or aren't working as expected.
For example, Samba on RPi4 sometimes has problems and throttles when I watch videos with Kodi on a FireTV. This happens after a while and is annoying, but basically Samba works and can provide files.Another problem is, connections to mosquitto aren't sucessful, see this log:
Jun 07 18:15:29 RPi4 mosquitto[682]: 1591546529: New connection from 10.10.10.59 on port 1883.
Jun 07 18:15:29 RPi4 mosquitto[682]: 1591546529: New client connected from 10.10.10.59 as DVES_ABCDEF (p2, c1, k30, u'DVES_USER').
Jun 07 18:15:44 RPi4 mosquitto[682]: 1591546544: Socket error on client DVES_ABCDEF, disconnecting.
Jun 07 18:15:49 RPi4 mosquitto[682]: 1591546549: New connection from 10.10.10.59 on port 1883.
Jun 07 18:15:49 RPi4 mosquitto[682]: 1591546549: New client connected from 10.10.10.59 as DVES_ABCDEF (p2, c1, k30, u'DVES_USER').
Jun 07 18:16:04 RPi4 mosquitto[682]: 1591546564: Socket error on client DVES_ABCDEF, disconnecting.
If I use the same SD card in my Pi3B, everything works fine and these errors don't occur.
I'll try again when the Arch Linux aarch64 kernel 5.7 is available.